3:11 For 1 this is the gospel 2 message 3 that you have heard from the beginning: that we should love one another, 4 3:12 not like Cain 5 who was of the evil one and brutally 6 murdered his brother. And why did he murder him? Because his deeds were evil, but his brother’s were righteous.
1 tn It could be argued (1) that the ὅτι (Joti) at the beginning of 3:11 is grammatically subordinate to the preceding statement at the end of 3:10. As BDF §456.1 points out, however, “Subordination with ὅτι and διότι is often very loose…and must be translated ‘for.’” Thus (2) ὅτι assumes an inferential sense, standing at the beginning of a new sentence and drawing an inference based upon all that has preceded. This is confirmed by the structural parallel between the present verse and 1:5.
5 sn Since the author states that Cain…was of the evil one (ἐκ τοῦ πονηροῦ, ek tou ponhrou), in the immediate context this imagery serves as an illustration of 3:8a: The person who practices sin is of the devil (ἐκ τοῦ διαβόλου, ek tou diabolou). This is similar to John 8:44, where Jesus told his opponents “you people are from your father the devil…[who] was a murderer from the beginning.” In both Jewish and early Christian writings Cain is a model for those who deliberately disbelieve; Testament of Benjamin 7:5 looks forward to the punishment of those who “are like Cain in the envy and hatred of brothers.” It is not difficult to see why the author of 1 John used Cain here as a model for the opponents in light of their failure to “love the brothers” (see 1 John 3:17).
6 tn For the Greek verb σφάζω (sfazw) L&N 20.72 states, “to slaughter, either animals or persons; in contexts referring to persons, the implication is of violence and mercilessness – ‘to slaughter, to kill.’” As a reflection of this nuance, the translation “brutally murdered” has been used.